This paper presents a method for writing-box-free online handwritten text search. It searches for a target keyword in the lattice composed of candidate segmentations and candidate characters. By considering the accuracy of the recognition method and the length of the keyword, the method decreases noises to be output from the lattice effectively. When the keyword consists of three characters, we have achieved the recall rate 89.4%, the precision rate 93.2% and F measure 0.912.